UC知道matlab求曲线满足斜率要求某点坐标
来源：百度知道 编辑：UC知道 时间：2024/05/16 15:49:45
x1=0:0.1:10;
x2=0:0.1:10;
x3=0:0.1:10;
y1=1.375*sqrt(0.1121/10000000*(3000/1000000-500/1000000)^3./(1.3/100000*(3000/1000000)^7+x1/1000000*(3000/1000000)^3*(3000/1000000-500/1000000)^3));
y2=1.375*sqrt(0.1121/10000000*(3200/1000000-500/1000000)^3./(1.3/100000*(3200/1000000)^7+x2/1000000*(3200/1000000)^3*(3200/1000000-500/1000000)^3));
y3=1.375*sqrt(0.1121/10000000*(3400/1000000-500/1000000)^3./(1.3/100000*(3400/1000000)^7+x3/1000000*(3400/1000000)^3*(3400/1000000-500/1000000)^3));
x=[x1;x2;x3]';
y=[y1;y2;y3]';
plot(x,y)
想找这个曲线的斜率为-1或-2等值时，这个点的坐标。如何求呢？
希望能给出程序 谢谢
x2=0:0.1:10;
x3=0:0.1:10;
y1=1.375*sqrt(0.1121/10000000*(3000/1000000-500/1000000)^3./(1.3/100000*(3000/1000000)^7+x1/1000000*(3000/1000000)^3*(3000/1000000-500/1000000)^3));
y2=1.375*sqrt(0.1121/10000000*(3200/1000000-500/1000000)^3./(1.3/100000*(3200/1000000)^7+x2/1000000*(3200/1000000)^3*(3200/1000000-500/1000000)^3));
y3=1.375*sqrt(0.1121/10000000*(3400/1000000-500/1000000)^3./(1.3/100000*(3400/1000000)^7+x3/1000000*(3400/1000000)^3*(3400/1000000-500/1000000)^3));
x=[x1;x2;x3]';
y=[y1;y2;y3]';
plot(x,y)
想找这个曲线的斜率为-1或-2等值时，这个点的坐标。如何求呢？
希望能给出程序 谢谢
syms x1 x2 x3
y1=1.375*sqrt(0.1121/10000000*(3000/1000000-500/1000000)^3./(1.3/100000*(3000/1000000)^7+x1/1000000*(3000/1000000)^3*(3000/1000000-500/1000000)^3));
dy1=diff(y1,x1,1)%斜率
x11=eval(solve(dy1-(-1)))%斜率等于-1时，x1的坐标值
y11=subs(y1,'x1',x11) %斜率等于-1时，y1的坐标值
x12=eval(solve(dy1-(-2)))
y12=subs(y1,'x1',x12)
同理，求y2,y3